Electronic code telegraph reading and repeating system



June 9, 1953 w, s, w. EDGAR, JR 2,641,651

ELECTRONIC CODE TELEGRAPH READING AND REPEATING SYSTEM Y Original Filed Feb. 15, 1949 Bs+ wm,- c7 RIO 1: All

All. All

III I III R16 INVENTOR -T w.s.w EDGAR JR.

Patented June 9, 1953 ELECTRQNI-C CODE TELEGRAPH READING AND ,REPEATING SYSTEM William Stanley 'Westerman Edgar, Jr., New York, N. Y., assignor to 'The"Western Union Telegraph .Company, New York, N. X" a 'cor- Duration of Nev 91k Original application February '15, 1949, Serial No, 76,486. Divided and this application January 12, 1951, Serial No, 205,659

14 C aims- V This invention relates to an electronic code telegraph signal storing, reading and repeating v system, and more particularly to such a system in which predetermined code impulses may be added to the code signals, if desired, and in which predetermined code signals may be identified and, if desired, eliminated from the repeated signals or utilized to perform selected functions.

{Ifhe present invention is a division of my copending application Serial No. 76,486, filed Febru-.- ary 15, 1949.

One aspect of the invention involves the conversion of multiplex signals into start-stop or similar signals. .Heretofore, it has'been the usual practice in converting from multiplex signals to simplex signals to use a circuit arrangement consisting of both mechanical relays and electron tubes. The present invention successfully eliminates the need for using mechanical relays and permits the conversion to be effected solely by means of electron tubes. This elimination of mechanical relays results in a lower initial cost and in an economy of installation space. ;It also provides lower maintenance cost and an ability to operate at far higher speeds with no sacrifice in reliability.

Thus, one of the objects of this invention is to provide an improved solely electronic means of converting multiplex signals into simplex signals.

Another object .of this inventionis to provide an electronic method of deleting blank signals received over the incoming circuit. This is accompli hed by a p ura t of r i g t e h ch tectblank signal codes and act upon the reception oisuch signals to produce amarking pulse in p1ace of the normally inserted spacing start pulse. 7

Other object and features of this invention will appear more clearly from the jollowingdescription taken in connection with the accompanying drawing which diagrammatically illustrates a manner of converting multiplex signals into'start-stop or simplex signals and for reading received blank signals and preventing their transmission over the outgoing simplex circuit. "Reierring now to-the drawing, a developedportion of the signal distributor is shown having multiplex receiving brushes Ill and simplex brushes I l with their respectively associated commen and segmented rings l2 I3 and l4, l5. s

The multiplex receiving ring l3 is divided into channels of five segments each, the segments of one channel being numbered consecutively I through 5 and the common or solid ring l2 being connected to the incoming line L. "The teleprinter timing ring i5 is also divided into segments l 2 through and ha in a i on three e r se ments R E d. S.- nn t to is n by mea-nsoi brushes l l is the common grounded ring l4. Brushes It and H are fixed to rotate simul-, taneously at the same relative position on the d s butor e brushe 011 h ri e tim n ring a so placed that shortly after all five segments on the multiplex ring have received their impulses, the brush on the teleprinter ring will contact sequence the segment R. E and S. Segment S is the startv segment and it is through this segment that the spacing signal needed to start the seven-unit teleprinter code is transmitted. After leaving the S segment the brush II will contact in succession segments I to 5 of. the teleprinter ring, which apply ground to tube circuits eners ze y t eme se ment 9n th u t plex i g as here na ter describe Af er g og-rid has been a li zto t e are tube circuits qnt olled .b the multiplex se ments .l is 5 he est msme t tz s a ain re ched on the teleprinter ring. This, as will be explained, causes arrest 9 m rkin impulse to :betransrnitted to the (Wi ins line t us com etin the :last unit of the sevengit teleprinter code; The .explorae er se ment E the te eprinter n a p es {to .a tube circuit arran ed to read blanks -c ed herei after in detail.

v 'I he fivesegments of ring 113 are connected, re+ specti-vely, to ;the grids of f ve receiving storage 5 141 8 1 5 th ou h series resistances R4 R2 having a grounded condenser CI connected there.- petween. .h; S as each signal impulse is-recei ved on the multiplex segments -it is stored in the associated conden ers C] and serves to maintain the gridsof tubes -81 to S5 charged either negatively or positively in accordance with the received signal impulses. The live receiving tube circuits are identical and therefore only that associated with multiplex segment I will be described.

Ifhe plate of tube :Sl is connected to positive batteryrBl through'a resistance R3 and negative battery B2 is connected thereto through a" neon lamp NLJ iandavoltage divider network comprisi-ng resistances R4 and R5. The cathode of tube SI :is connected to ground through resistance R8 and to negative battery iBZ through a voltage divider network comprising resistances R6 and R7. I. W

Thetube SI determines the operation of either one of two tubes 1M! and IS} depending upon the-operativeor inoperative condition or'tube'si For this purpose the grid of tube IM I is connected between the voltage divider resistances RI and cathodes of the remaining tubes 1M2 to 1M5 and 182 to 1S5 are similarly connected, respectively, to the simplex segments 2 to of ring I5. The anodes of tubes IMI to 1M5 are connected in parallel through the primary winding of ,a transformer TCM to positive battery B3. The primary of transformer 'ICM is also connected through a condenser C6, a resistance R9 and conductor I1 to the rest segment R of the simplex distributor ring.

to the opposite plate thereof from battery B3 and as a result of which whenever the simplex brush II grounds segment R, charging current flows from the condenser C6 through the primary .of transformer TCM, to thereby transmit a rest impulse to line,'as will subsequently appear. The signals consecutively received on the multiplex segments I through 5 of ring I3 have either a positive or a negative polarity, depending on whether spacing or marking signals are being received from the line. The circuit is arranged to operate with a negative marking condition and a positive spacing condition. By switching the lead XI, connected to the grid of tube IMI with the lead YI connected to the grid of the tube IS I this circuit will work from a multiplex channel that marks on positive battery. For the sake of simplicity we will describe the circuit as it is set up, i. e., arranged to operate from a multiplex channel which marks on negative battery.

It should be noted that although only one channel of five multiplex segments of ring I3 and the corresponding teleprinter segments of ring I5 are depicted on the circuit diagram, any number of channels, consistent with limitations of space, may be provided.

The operationof the circuit for the channel shown will be described and this description will suffice forany number of channels. For this purpose an arbitrary combination of signals received over the'first channel will be selected. Assume that the combination selected consists of impulses conventionally stated as marking, spacing, spacing, marking, marking or impulses which are This is letter B of the Baudot code.

Such being the case, the first received impulse will be a negative or marking signal on the common ring I2 from which it will be applied through multiplex segment I of ring I3 to the storage condenser CI. It is necessary to store the Baudot ,code units long enough to enable the starting pulse, which will be described in detail below, to initiate transmission of the received code over the teleprinter line. This is accomplished in part by making the discharge path of the condenser to the grid of tube SI of such high resistance that the condenser will hold its charge for one revolution. The resistance R2 serves this purpose. The resistance BI is a protective device for segment I .of ring I3 from the residual charge on condenser CI.

The negative impulse coming from segment I places a negative potential on the grid of tube SI so that this tube will remain unoperated. It will be recalled that the potential on the grid of tube IMI is regulated by the connection from the anode of the tube SI to the grid of the tube IMI;

The condenser C6 is normally retained uncharged by the positive battery B4 connected and the potential across the grid of the tube ISI is regulated by the connection between the oathode of the tube SI and the grid of the tube ISI. With the tube SI in a non-conducting condition the voltage divider network operates inthe following manner. A positive potential from battery connection BI will be applied through resistor R3,

the neon lamp NLI and resistor R4 to the grid of tube IMI This positive potential will be of sulficient value to cancel out the negative potential coming from battery connection B2 through resistor R5 and tojapply the proper positive potential to the grid of tube IMI. However, at this time the cathode circuit of tube IMI is open at the simplex segment I of ring I5.

With tube SI non-conducting, as stated, the

v grid of tube ISI receives a negative potential from battery connection B2 through resistor R1 making tube ISI also non-conducting.

The multiplex brush next makes contact with segment 2 on the multiplex receiving ring I3 and a positive charge is stored on the condenser C2 associated with this segment as in the circuit described above. Thi being a positive signal, however, it causes the grid of tube S2 to be driven positive thus making the tube conducting and thereby providing a shunt path from battery BI to the grid of tube 182, thus rendering this tube positive and causing the-grid of tube 1M2 to be charged negativelyfrom battery B2. Tube 1S2 thus becomes conditioned for operation upon the completion of its cathode circuit through simplex segment 2 of ring I 5.

After a pulse, of either negative or positive polarity, has been stored in all five circuits connected to segments I to 5 of the multiplex receiving ring I3, to condition one or the other of each pair of tubes IMI to 1M5 and ISI to 135, the brush I I passes over segments R. and E, the purpose of which will be hereinafter described and then makes contact with the starting segment S. Thus, a ground is applied from segment S to one side of condenser C1. through the primary winding of transformer TCS and resistance RIB, to the ungrouncled side of condenser 01. As brush II moves from segment S, ground is removed from this segment causing a potential to be induced in the secondary winding of transformer TCS, in opposition to the negative battery 31, thereby making the grid of a tube'OCS positive and rendering the tube cone ducting.

The tube 00s is connected to the tube OCM in a conventional .trigger circuit which operates on the principle that only one tube at a time may pass plate current. Thus the plate potential for tubes DOS and OCM is supplied from battery B8 through the resistances RI I and RI2 respectively, and'the grid of each tube is provided with a positive bias from the plate potential of the other tube, through limiting resistances RI3 and RM, respectively. An opposing negative potential is supplied to the grid of tube OCS from battery B'I, resistance RIB and the secondary winding of transformer TCS. Likewise, the grid of tube OCM is connected to negative battery 3'! through resistance RIG and the secondary winding of transformer TCM.

Normally, with no signals being transmitted the marking tube OCM will be conducting and will shunt out the positive biasingpotential for tube OCS so that the grid of this tube is held neg- .ative by battery B]. I v An output tube OT having its grid also connected through resistances RI I and RI! to the This results in'a pulse positive battery B8, in opposition to its negative grid bias B9, is conducting at this time. i

' However, upon the generation of a positiv pulse through transformer TCS by the start segment S, as described, the grid of tube OCS is driven strongly positive and it becomes conducting, extinguishing tube OCM. The operation of tube 003 shunts out the positive grid bias for the output tube OT and this tube becomes nonconducting thereby transmitting a start or spacing signal to line. Thus, the space signal necessary to start the teleprinter code is transmitted and it-is now time to transmit the five code impulses of the received character signal. The brush H on the teleprinter timing ring l5 now moves on the ring for a space equal to one impulse period and contacts segment I. Thus a ground is supplied over conductor [6 to the oathodes of the tubes IMI and ISI. In the example assumed, as will be recalled, the grid of tube IMI was made positive due to the negative charge stored in condenser Cl. With the ground thus applied, tube IMI becomes conducting and sends a pulse through the primary winding of transformer TCM. The secondary winding of. this transformer receives the pulse through normal transformer action and applies the resulting positive potential to the grid of tube OCM. This positive potential causes tube OCM to conduct and by .virtue of the trigger circuit, explained above, tube OCS become non-conducting- The circuit is arranged, through the shown resistors,

so that when tube OCM is conducting, a positive potential of sufiicient strength to operate the output tube OT is'applied to the grid of this tube which thereby marks the teleprinter line. In a like manner, the four remaining impulses of the code are transmitted to the teleprinter line.

After the ground has been applied to the fifth segment of ring it to transmit the final impulse of the code signal, it contacts rest segment B. This segment reacts in the same manner as segment S by grounding condenser C6. This condenser, however, is connected to the primary winding of transformer TCM, instead of transformer TCS. Therefore, the secondary winding of, transformer TCM will apply a positivepotential across the grid, of tube OCM and, by virtue of the trigger circuit action, the output tube OT will mark the teleprinter line. This. completes the transfer of the five-unit multiplex code into the seven-unit, start-stop or teleprinter code. It should be noted that the segments on the teleprinter timing ring are so orientedthat, for example, while a ground is applied to the circuits of segments 3 and 4 of the teleprinter ring, segments, 1 and 2' of the multiplex ring are receiving their next signal impulse.

The circuit as described above would also transmit to the teleprinter line each blank or all spacing signal received, since it would be stored in the condensers connected to the tubes SI to S5 as positive potentials and therefore would space the teleprinter line the same as any other signal. To prevent repetition of these blank signals over the teleprinter line, aaway has been'devised by which tube OCS will not .be able to conduct despite the positive potential imposed upon its grid v 6 cathode or anode, controls the grid of a comparison tube T! to- T5.. All of the. tubes TI to T5 have common plate and cathode resistors R2! and RES, respectively. Resistances RIB and R20 and neon lamp -NL6 forma voltage divider network connected to the grid of tube O-Rn Likewise the resistances R22 and R23 form a voltage die vider network connected to the grid of tube BR. The grids of tubes TI to T5 are connected to the grids of the corresponding tubes IMI .to 1M5 so as to respond to received marking and spacing signals in thesame manner as tubes IMI to 1M5.

If all of the condensers connected to the grids of tubes SI to S5 receive a positive charge (1. e., a blank or all spacing signal is registered) none of tubes TI to T5 willbecome conducting. This occurs as a result of the positive charge being placed on the grids of tubes S1 to S5 thus rendering each of. the tubes SI to S5 conducting. Hence, a positive potential is applied from battery connection BI through R3 and R6 to the grids of each of the tubes IS and consequently a negative potential is applied to all of the tubes IMI to 1M5 and TI to T5 from battery connection B2, through resistance R5.

Thus with all five of the tubes Ti to'T5nonconducting, the voltage divider networks are'so connected'to. the grids of tubes OR and BR, as to regulate those tubes in the following manner:

A positive potential is normally applied to the grid of tube BR through resistances R21 and R22. Resistances RZI, R22 and R23 are so selected that, with tubes Ti to T5 non-conducting, this positive potential will be greater than the negative potential applied at 'the'terminal of resistance R23, and the grid of tube BR. will thereby be maintained positive. At the sametime, the grid of tube OR will be maintained negative due to thenegative potential from batteryatthe terminal of resistance R28; In order for tube OR or BRito pass current, a groundmust -be applied to the cathodes of the two tubes. This is accomplished by'the exploratory segment E on theteleprinterring. After the "five impulses arestored on condensers Ci to C5 and before Jstarting'segment S is reached, the brush I l reaches explora tory segment E which grounds the cathodes =01 tubes OR and BB. I

Sin'ce-thegrid of tube BB is positive, it becomes conducting "causing a current'flow" through the primarywinding of transformer TBR; which thus induces a positive pulse in its secondary winding from where it is transmitted to the grid of tube J BRL. Tubes BBL and ORL are connected in a conventional trigger circuit just as tubes 00S BRL to the. grid of tube OCM; This high positive potential on the grid of OCM will-prevent the smaller positive potential-on the grid of tube 003 iromzworking the trigger circuit (i. e.,'making tube OCM non-conducting) andhence the circuit locks and no change is sent to the output tube controlling the teleprinter line, and therefore the received blank signal is not transmitted; Tube BBL continues to operate and block transmission of spacing impulses over the outgoing line until a character other than blank is received from. the multiplex line. a

.7. Whena character other than blank is received, v

one or more of the five condensers CI to C connected to the tubes SI to S5 will receive a marki l pulse and will result in one of the tubes TI to T5 becoming conducting. Thus, with any one of the tubes TI to T5 conducting, the voltage drop occurring through resistance R2! causes the negative battery at the terminal of resistance R23 to predominate so as to drive the grid of tube BR negative and the positive potential impressed through one or more of the operating tubes TI to T5, neon lamp L6 and resistance RI 9 predominates over the negative potential from the terminal of resistance R29 so that the grid of tube OR is driven positive.

Thus, when the ground is applied at segment E,

tube OR becomes conducting causing current flow through the primary Winding of transformer TO-R and inducing a positive charge in the secondary winding of TOR. Tube ORL thus receives a positive grid potential, making it conducting. It thereby operates the trigger circuit which extinguishes tube BRL and interrupts the high positive bias to the grid of tube OCM. The trigger circuit, made up of tubes OCM and 008, is thus allowed to function normally. Thus, it will be noted, a purely electronic arrangement has been provided for converting multiplex signals into simplex or start-stop signals and for eliminating blank signals from retransmission.

While the invention has been described in a particular use thereof and in a particular embodiment, it is not desired that it be limited thereto for obvious modifications thereof will occur to those skilled in the art Without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. Apparatus for repeating permutation code telegraph signals having a uniform number of selecting impulses of marking and spacing conditions from an incoming circuit, comprising a plurality of receiving electronic devices, one individual to each unit of the permutation code signals, each of said receiving devices having an input circuit and an output circuit, a distributor for applying the signal impulses received over said incoming circuit selectively to the input circuits of said receiving electronic devices thereby selectively to render said receiving electronic devices conductive and nonconductive in accordance with said signal impulses, a pair of electronic selector devices individual to each of said receiving devices, each of said selector devices having an input circuit and an output circuit, means intercoupling the output circuits of said receiving electronic devices and the respective input circuits of the corresponding pairsof electronic selector devices in such manner that one of the electronic devices in each pair of selector devices is in conductive condition only when the corresponding receiving electronic device is conducting and the other electronic device in each pair of selector devices is in conductive condition only when the corresponding receiving electronic device is non-conducting, and means to derive from the output circuits of said electronic selector devices a permutation code telegraph signal corresponding to said received signal impulses.

zpApparatus for repeating permutation code telegraph signals having a uniform number of selecting impulses of marking and spacing conditions from an incoming circuit, comprising a plurality of receiving electron discharge tubes one individual to each unit dine-permutation code signals, each of said :tubeshaving an input. circuit and an output circuit, a distributor for applyin the signal :impulses received over said incoming circuitselectively to the input circuits of said receiving tubes thereby selectively to render said receiving tubes conductive and non-conductive in accordance with the, polarity of. said signal impulses, a pair of selector electron discharge tubes individual to each of said receiving tubes each having an input circuit and an output circuit, meansfiintercoupling the output circuits of said receiving tubes and the respective input circuits of the corresponding pairs of. selector tubes in such manner that one of tubes in each pair of selector tubes is in conductive condition only when the corresponding receiving tube is conducting and therother tube in each pair of selector tubes is in conductive condition only when thecorresponding receiving tube is non-conducting, and means to derive from the output circuits of said selector tubes apermutation code telegraph signal corresponding to said received signal impulses.

"3. Apparatus for repeating permutation code telegraph signal impulses from an incoming circuit, comprising a plurality of receiving electron discharge'tubes each having an input circuit and an output circuit, a distributor for applying the signalimpulses received over said incoming circult selectively to the inputcircuits of said re-' ceiving tubes thereby selectively to render said receiving tubes conductive andnon-c'onductive in accordance withthe polarity of said signal impulses, a plurality of pairs of selector electron dis-charge tubes each having 'an input circuit and an output circuit, 'a plurality of voltage divider networks each intercoupling the output circuit of a respective one of said receiving tubes and-the respective input circuits of the corre sponding pairs of selector tubes, said voltage divider networks being arranged in such manner that one ofthe tubes in each pair of selector tubes is in conductive condition only when the corresponding receiving tube is conducting and the other tube in 'each pair of selector tubes is in conductive condition only when the corresponding receiving tube is non-conducting, and means to derive from the output circuits of said selector tubes permutation code telegraph sig-' nal corresponding to said received signal impulses.

4'; Apparatus for repeating permutation code telegraph signalim'pulse's from an incoming circuit, comprising a plurality of receiving electron discharge tubes each having an input circuit and an output circuit, a distributor for applying the signal impulses received over said incomingcircuit selectively to the input circuits of-said receiving tubes thereby selectively to render said receiving tubes conductive and nonconductive in accordance with the polarity of said signal impulses, a plurality of pairs of selector electron discharge tubes each having an input circuit, and a normally 'open output circuit, a plurality of voltage divider networks each intercoupling the output circuit of a respective one of said receivin tubes and the respective input circuits of the corresponding pair of selector tubes; said voltage divider networks being arranged in such manner thatone of the tubes in each pairof selector tubes is in con-- ductive condition only when the corresponding receiving tube is conducting and the other tube in each pair'of'selector tubes is in conductive 119 condition only when the. corresponding receiving tube is non-conducting, means for completing the .output circuits of each pair of selector tubes in sequential order, signal repeating .means associated with the output circuits of said selector tubes and selectively responsive to the operation of said pairs of selector tubes, and means cuit selectively to the input circuits of said receiving tubes thereby selectively to. render said receiving tubes conductive and non-conductive,

in accordance with, the polarity of'said signal im-' pulses, a plurality of pairs of selector electron discharge tubes each having an input circuit and -a normally open output circuit, a plurality of voltage divider networks each. intercoupling the output circuit of a-respective one of said receiving tubes and the respective inputcircuits of the corresponding pair of selector tubes, said voltage dividernetworks being arranged in such manner that one of the tubes, in each pair of selector tubes is in conductive condition only when a positive signal impulse is applied to the input circuit -of the corresponding receiving tube and the other tube in each pair of selector tubes is in conductive condition only when a, negative signal impulse is appliedto the input circuit of the correspondingreceiving tube, means for completing the output circuits of each pair of selector tubes in sequential order, signal repeating means associated with the output circuits of said selector tubes and selectively responsive to the, operation of said pairs of selector tubes, and means to derive from saidv repeating means a permutation code telegraph signal corresponding to said received signal impulses.

6. Apparatus for repeating permutation code telegraph signal impulses from an incoming circuit, comprising a plurality of receiving electron discharge tubes each having an input circuit intercoupling the grid and cathode electrodes of the respective receiving tubes and an output circuit intercoupling the anode: and cathode electrodes of the respective receiving tubes, a' dis-'- tributor for applying the signal impulses received over said incoming circuit selectively to the input circuits of said receiving tubes thereby se- 10 the corresponding receiving tube, means for completing the output circuits of each pair ofselector tubes insequential order, signal repeating means associated with the outputcircuits of said selector tubes and selectively responsive to the operation of said pairs of selector tubes, and means to derive from said repeating means a permutation code telegraph signal corresponding to said received signal impulses.

'7. Apparatus for repeating'permutation code telegraph signal impulses from an incoming circuit, comprising a plurality of receivingelectron discharge tubes each having an input circuit and output circuit, a distributor for applying the signal impulses received over said incoming circuit selectively to the input circuits of said receiving lectively to render said receiving tubes conductive and non-conductive in accordance with the-polarity of said signal impulses, a plurality of pairs of selector electron discharge tubes each having an input circuit and a normally open output circuit, a first plurality of voltage divider networks each intercoupling the input circuit of one of the tubes in each of said pairs of selector tubes and the anode electrodes of the respective receiving tubes thereby to place said one tube in each of said pairs in conductive conditionsolely when a negative impulse is applied to the input circuit of the corresponding receiving tubes, "a second plurality of voltage divider networks each i ntercoupling the input circuits of the other tubes in each of said pairs of selector tubes and the cathode electrodes of the respective receiving tubes thereby to place said other tube in each of said pairsin conductive condition solely when a positive impulse is applied to the input circuit oftubes thereby selectively to render said receiving tubes conductive and non-conductive in accordance with the polarity of'said signal impulses, a plurality of pairs of selector electron discharge tubes each having an input circuit'and a normally openoutp-ut circuit, a plurality of voltage divider networkseach intercoupling the output circuit of a respective one of said receiving tubes and the respectiveinput-circuits of-the corresponding pair of selector tubes, said voltage divider networks being arranged in such manner that one of the tubes in each pair of selector tubes. is in conductive condition only when a positive signal impulse is applied to the input circuit of the corresponding receiving tube and the other tube in eachpair of selector tubes is in conductive condition only when a ne ative signal impulse is applied to the input circuit of the corres onding receiving tube; means or completing the output circuits of each pair of selector tubes in sequential order, a signal repeating circuit-including a pair of signal repeating electron discharge tubes, one of said repeatingtubes being associated in. common with the output circuits of one of the tubes in each of said pairs of selector tubes and the other repeating tube being associated in common with the output circuits of the other of the tubes in each of said pairs of selector tubes whereby one of said repeating tubes is rendered conductive solely when one of said tubes of said pairs of selector tubes is conductive and theother of said repeating tubes, is rendered conductive solely when one of said 'other tuhes of 7 [said pairs of-selector tubes is conductive,"saidjre peatin-g tubes being arranged in trigger relationship whereby conduction of one repeating tube causes a discontinuance of the conduction of the other repeating tube, and means to derive from said repeating circuit a permutation code telegraph signal corresponding to said receiv'ed'signal impulses.

. 8. Apparatus for repeating permutationfcode telegraph signal. impulses from an incoming circuit, comprising-a plurality of receiving electron discharge tubes each having an input circuit intercoupling the grid and cathode electrodes of the respective receiving tubes and an output circuit intercoupling the anode and cathode electrodes of the respective receiving tubes, a distributor for applying the signal impulses received over said incoming circuit, selectively tothe input circuits of said receiving tubes thereby selectively to render sa id receiving tubes conductive andinon-conductive in'accordance with the polarity of said signal impulses, a plurality of pairs of selector electron discharge tubes eachjhaving an'input 11 7 each of'said pairs of selector tubes and the anode electrodes of the respective receiving tubes thereby to place said one tube in each of said pairs in conductive condition solely when a negative imorder, a signal repeating circuit including a pair of signal repeating electron discharge tubes, one of said repeating tubes being associated in common with the output circuits of said one tubes in each of said pairs of selector tubes and the other repeating tube being associated in common with the output circuits of said other tubes in each of said pairs of selector tubes, whereby said one of said selector tubes is rendered conductive solely when one of said one tubes of said pairs of selector tubes is conductive and the other of said repeating tubes is rendered conductive solely when one of said other tubes of said pairs of selector tubes is conductive, said repeating tubes being arranged in trigger relationship whereby conduction of one repeating tube causes a discontinuanceof conduction of the other repeating tube, and

means selectively responsive to the conduction of said repeating tubes to derive from said repeating circuit a permutation code telegraph signal corresponding to said received signa1 impulses.

9. Apparatus for repeating permutation code telegraph signal impulses from an incomingcircuit, comprising a plurality of receiving electron discharge tubes each having an input circuit and an output circuit, a first distributor for applying the signal impulses received over said incoming circuit selectively to the input circuits of said receiving tubes thereby selectively to render said receiving tubes conductive and non-conductive in accordance with the polarity of said signal impulses, a plurality of pairs of selector electron dis charge tubes each having an input circuit and a normally open output circuit, a plurality of volt-,

age divider networks each intercoupling the output circuit of a respective one of said receiving tubes and the respective input circuits of the corresponding pair of selector tubes, said voltage divider networks being arranged in such manner that one of the tubes in each pair of selector tubes is in conductive condition only when ajpositivesignal impulse is applied to the input circuit of the corresponding receiving tube and the other tube in each pair of selector tubes is in conductive condition only when a negative signal impulse is applied to the input circuit of the corresponding receiving tube, signal repeating means asso ciated with the output circuits of said selector tubes and selectively responsive to the operation of said pairs of selector tubes, means including a second distributor for sequentially generating and transmitting to said repeating means a start signa1 indication, completing the output circuits of each pair of selector tubes in sequential order and generating and transmitting to said repeating means a rest signal indication, and means to derive from said repeating means a permutation code telegraph signal corresponding to said received signal impulses and having start and rest signal impulses.

10. Apparatus for repeating permutation code marking and spacing telegraph signal impulses from an incoming line and for preventing repetition of signals constituted solely'by spacing impulses, comprising a plurality of receiving electronrdischarge tubes each having an input cir cuit and an output circuit, a distributor for applying the signal impulses received over said incoming circuit selectively to the input circuits of said receiving tubes thereby selectively to render said receiving tubes conductive and non-conductive in accordance with the polarity of said signal impulses, a plurality of pairs of selector electron discharge tubes each having an input circuit and a normally open output circuit, a plurality of voltage divider networks each intercoupling the output circuit of a respective one of said receiving tubes and the respective input circuits of the corresponding pairs of selector tubes, said voltage divider networks being arranged in such manner that one of the tubes in each pair of selector tubes is in conductive condition only when the corresponding receiving tube is conducting and the other tube in each pair of selector tubes is in conductive condition only when the corresponding receiving tube is non-conducting, means for completing the output circuits of each pair of selector tubes in sequential order, signal repeating means associated with the output circuits of said selector tubes and selectively responsive to the operation of said pairs of selector tubes, means to suppress operation of said signal repeating 7 means when said received signal impulses are constituted solely of spacing impulses comprising a plurality of reading electron discharge tubes each having an input circuit coupled to a respective one of the output circuits of said receiving tubes and having an output circuit, each of said reading tubes having a conductive condition and a non-conductive condition, the coupling of the input circuits of said reading tubes to the respective output circuits of said receiving tubes being arranged in such manner that said reading tubes are caused to assume one of said conditions upon application of spacing impulses to the input circuits of the associated receivin tubes and means operative when all of said reading tubes are in said one of said conditions to prevent operation of said signal repeating means, and means to derive from said repeating means a permutation code telegraph signal corresponding to said received marking and spacing telegraph signal impulses.

11. Apparatus for repeating permutation code negative and positive telegraph signal impulses from an incoming line and for preventing repe-' tition of'signals constituted solely by spacing impulses, comprising a plurality of receiving electron discharge tubes each having an input circuit and an output circuit, a distributor for applying the signal impulses received over said incoming circuit selectively to the input circuits of said receiving tubes thereby selectively to render said receiving tubes conductive and non-conductive in accordance with the polarity of said signal impulses, a plurality of pairs of selector electron disc'hargetubes each having an :input circuit and a normally open output circuit, a plurality of voltage divider networks each intercoupling the output circuit of a respective one of said receiving tubes and the respective input circuits of the corresponding pairs of selector tubes, said voltage divider networks being arranged in such mannerthat one of the tubes in each pair of selector tubes is in conductive condition only when the receiving tube is conducting and the other tube in each pair of selector tubes is in conductive condition only when the corresponding receiving tube is nonconducting, means for completing the output circuits of each pair of selector tubes in sequential order, signal repeating means associated with the output circuits of said selector tubes and selectively responsive to the operation of said pairs of selector tubes, means to suppress operation of said signal repeating means when said received signal impulses are constituted solely of positive impulses comprising a plurality of reading electron discharge tubes each having an input circuit coupled to a respective one of the output circuits of said receiving tubes and having an output circuit, each of said reading tubes having a conductive condition and a non-conductive condition, the coupling of the input circuits of said reading tubes to the respective output circuits of said receiving tubes being arranged in such manner that said reading tubes are caused to assume said non-conductive condition upon conduction of the associated receiving tube and means operative when all of said reading tubes are in said non-conductive condition to prevent operation of said signal repeating means, and means operative when said reading tubes are not all in said non-conductive condition to derive from said repeating means a permutation code telegraph signal corresponding to said received telegraph signal impulses.

12. Apparatus for repeating permutation code telegraph signal impulses from an incoming circuit, comprising a plurality of receiving electronic systems each having an input circuit and an output circuit, a distributor for applying the signal impulses received over said incoming circuit selectively to the input circuits of said receiving systems thereby selectively to render said receiving systems conductive and non-conductive in accordance with the polarity of said signal impulses, a plurality of pairs of selector electronic systems each having an input circuit and a normally open output circuit, a plurality of voltage divider, networks each intercoupling the output circuit of a respective one of said receiving systems and the respective input circuits of the corresponding pair of selector systems, said voltage divider networks being arranged in such manner that one of the systems in each pair of selector systems is in conductive condition only when a positive signal impulse is applied to the input circuit of the corresponding receiving system and the other system in each pair of selector systems is in conductive condition only when a negative signal impulse is applied to the input circuit of the corresponding receiving system, means for completing the output circuits of each pair of selector systems in sequential order, signal repeating means associated with the output circuits of said selector systems and selectively responsive to the operation of said pairs of selector system, and means to derive from said repeating means a permutation code telegraph signal corresponding to said received signal impulses.

13. Apparatus for receiving permutation code telegraph signal groups having a uniform number of selecting impulses of marking and spacing conditions, comprising a receiving electronic having an input circuit coupled to the output circuit of its corresponding receiving device for operation selectively in accordance with the conducting or non-conducting condition of its corresponding receiving device, a normally open output circuit for each of said electronic means, means for closing said output circuits in sequential order and in timed relation to the distribution of the signal impulses to the corresponding receiving device and means for deriving telegraph code signal groups from the output circuits of said electronic means.

14, Apparatus for receiving permutation code telegraph signal groups having a uniform number of selecting impulses of marking and spacing conditions, comprising a receiving electronic device individual to each unit of a signal group, each of said devices having an input circuit and an output circuit, means for distributing the impulses of each signal group to the input circuits of said receiving devices in sequential order to render said receiving devices selectively conducting or non-conducting in accordance with the marking or spacing condition of said signal impulses, means for maintaining said receiving devices in said conducting ornonconducting condition after cessation of said signal impulses, electronic means individual to each of said receiving devices, each of said electronic means having an input circuit coupled to the output circuit of its corresponding receiving device for operation selectively in accordance with the conducting or non-conducting condition of its corresponding receiving device, a normally open output circuit for each of said electronic means, means for closing said output circuits in sequential order and in timed relation to the distribution of the signal impulses to the corresponding receiving device, means for deriving telegraph code signal groups from the output circuits of said electronic means and means for interposing supplemental signal impulses between successive derived code signal groups.

WILLIAM STANLEY WESTERMAN EDGAR, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,365,450 Bliss Dec. 19, 1944 2,465,185 Anderson Mar. 22, 1949 FOREIGN PATENTS Number Country Date 840,607 France -l-.. Jan, 23, 1939 

